Horseshoe Crab Anatomy
- The body of the horseshoe crab is divided into three regions: the prosoma, opisthosoma, and the telson.
- The entire body is protected by a hard shell known as a carapace.
- The horseshoe crab has two primary compound eyes and seven secondary simple eyes. Two of the secondary eyes are located on the bottom of the animal.
- The internal anatomy of the horseshoe crab is similar to that of spiders. Similar to the book lungs of spiders, horseshoe crabs possess book gills which function in gas exchange and are also used for swimming.
- The horseshoe crab has five pairs of legs for walking, swimming, and moving food into the mouth.
- The long tail, known as the telson, can be used to flip the horseshoe crab over if it is turned upside down.
- Horseshoe crabs usually swim upside down. However, they are most often on the ocean floor searching for food.
- Females are larger than males.
References:
Ecological Research & Development Group (ERDG): The Horseshoe Crab. c2002-2009. Dover, DE. http://horseshoecrab.org/
Pechenik, JA. Biology of the Invertebrates, sixth edition. New York, NY: McGraw Hill Higher Education, 2010.
Pechenik, JA. Biology of the Invertebrates, sixth edition. New York, NY: McGraw Hill Higher Education, 2010.